Buick TERRAZA 2006 Owner's Manual page 193

To adjust for compass variance, use the following
procedure:
1. Press the menu button until COMPASS ZONE
displays.
2. Find the vehicle's current location and variance
zone number on the map.
3. Press the set/reset button to scroll through and
select the appropriate variance zone.
4. Press the menu button to advance to the
COMPASS CALIBRATION screen.
5. To start the compass calibration, press and hold the
set/reset button until CALIBRATION BEGUN DRIVE
UNTIL DONE appears in the DIC display.
6. Drive the vehicle slowly in a circle two times to
activate the compass.
When the calibration is complete, the DIC will
display CALIBRATION FINISHED.
7. If the message CAL appears in the DIC, you must
manually put the compass into the calibration mode
again. Repeat Steps 1 through 6.
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